semi-automatic style(9)
The futex stuff already differs a lot (only a small part does not differ)
from NetBSD, so we are already way off and can't apply changes from NetBSD
automatically. As we need to merge everything by hand already, we can even
make the files comply to our world order.
- Dont "return" in linux_clone() after we forked the new process in a case
of problems.
- Move the copyout of p2->p_pid outside the emul_lock coverage in
linux_clone().
- Cache the em->pdeath_signal in a local variable and move the copyout
out of the emul_lock coverage.
- Move the free() out of the emul_shared_lock coverage in a preparation
to switch emul_lock to non-sleepable lock (mutex).
Submitted by: rdivacky
cannot change (because its referenced by curthread). This fixes
a LOR caused by acquiring emul_shared_lock while holding emul_lock.
Fix typo in comment.
Submitted by: rdivacky
p->p_emuldata is properly initialized in the time when the child can run.
Do not set p->p_emuldata to NULL when the process is exiting.
It does not make any sense and only costs 2 mutex operations.
Do not lock emul_data to unlock it on the very next line.
Comment on possible race while there.
Reparent all procs that are part of a threading group but not its leaders
to init and SIGCHLD init to finish the zombies off. This fixes zombies
left after opera's exit. [1]
There is no need to lock p_em in the linux_proc_init CLONE_THREAD
case because the process cannot change the address of the p_em->shared
because its currently running this code path.
Move assigning of em->shared outside emul_shared_lock.
Noticed by: Scott Robbins <scottro@nyc.rr.com> [1]
Submitted by: rdivacky
Dont expose em->shared to the outside world before its properly
initialized. Might not affect anything but its at least a better
coding style.
Dont expose em via p->p_emuldata until its properly initialized.
This also enables us to get rid of some locking and simplify the
code because we are workin on a local copy.
In linux_fork and linux_vfork create the process in stopped state
to be sure that the new process runs with fully initialized emuldata
structure [1]. Also fix the vfork (both in linux_clone and linux_vfork)
race that could result in never woken up process [2].
Reported by: Scot Hetzel [1]
Suggested by: jhb [2]
Reviewed by: jhb (at least some important parts)
Submitted by: rdivacky
Tested by: Scot Hetzel (on amd64)
Change 2 comments (in the new code) to comply to style(9).
Suggested by: jhb
to open() [1].
Improve locking for accessing session control structures [2].
Try to document (most likely harmless) races in the code [3].
Based on submission by: Intron (intron at intron ac) [1]
Reviewed by: jhb [2]
Discussed with: netchild, rwatson, jhb [3]
Now (ok it's been a while...) that FreeBSD has RLIMIT_AS too, we can use
it in the linuxolator instead of ignoring it.
This fixes a LTP test.
Submitted by: rdivacky
No need to lock prison in a case of linux_use26 because the int
setting is atomic and process cannot leave jail.
Submitted by: kib
Reviewed by: jhb
Requested by: rdivacky
Dont lock em in a case of just using em->shared->group_pid because
the group_pid never changes.
Submitted by: rdivacky
Reviewed by: kib
Glanced at by: jhb
Redo the checking for 2.6 emulation. We now cache the value of
use26 and replace calls to linux_get_osrelease() + parsing with
a call to linux_use26(). Typical path is lockless now.
Pointed out by: kib
This allows to ship RELENG_7_0 with a default osrelease of 2.4.2 and the
possibility to enable 2.6.x emulation without the possible performance
impact of the previous version of the check.
Submitted by: rdivacky
- Move linux_nanosleep() from src/sys/amd64/linux32/linux32_machdep.c to
src/sys/compat/linux/linux_time.c.
- Validate timespec ranges before use as Linux kernel does.
- Fix l_timespec structure.
- Clean up style(9) nits.
Add rudimentary IPC_INFO/MSG_INFO command support for linux_msgctl()
to pacify Linux ipcs(1). While I am here, add more bound checks
for linux_msgsnd() and linux_msgrcv().
Fixes for 'blocking in fifoor state' problem of LTP tests.
linux_*stat*() functions were opening files with O_RDONLY to get
major/minor pair for char/block special files. Unfortunately,
when these functions are used against fifo, it is blocked forever
because there is no writer. Instead, we only open char/block special
files for major/minor conversion. We have to get rid of kern_open()
entirely from translate_path_major_minor() but today is not the day.
While I am here, add checks for errors before calling
translate_path_major_minor().
- Currently LINUX_MAX_COMM_LEN is smaller than MAXCOMLEN, but in case
this will change we have a buffer overflow. Apply some defensive
programming to DTRT when this should happen.
- Use copyinstr() instead of copyin where appropriate.
* Fallback to copyin() in case of ENAMETOOLONG. [1]
* Use the right source and destination (it was wrong before).
- Use strlcpy instead of strcpy.
- Properly lock the read case (PR_GET_NAME) like the write case.
Reviewed by: rwatson (except [1])
Suggested by: rwatson [1]
This fix lets clone02 LTP test pass with 2.6 emulation. In reality 99%
of the cases are that CLONE_VM and CLONE_THREAD are both set so it
seemed to work.
Submitted by: rdivacky
__WCLONE. This fixes it thus fixing skype/teamspeak to not keep zombies
after exit.
Submitted by: rdivacky
Reported by: Bakul Shah (bakul at bitblocks com)
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
dynamic nature (if no native aio code is available, the linux part
returns ENOSYS because of missing requisites) should be solved differently
than it is.
All this will be done in P4.
Not included in this commit is a backout of the changes to the native aio
code (removing static in some places). Those changes (and some more) will
also be needed when the reworked linux aio stuff will reenter the tree.
Requested by: rwatson
Discussed with: rwatson
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
Implement the linux_io_* syscalls (AIO). They are only enabled if the native
AIO code is available (either compiled in to the kernel or as a module) at
the time the functions are used. If the AIO stuff is not available there
will be a ENOSYS.
From the submitter:
---snip---
DESIGN NOTES:
1. Linux permits a process to own multiple AIO queues (distinguished by
"context"), but FreeBSD creates only one single AIO queue per process.
My code maintains a request queue (STAILQ of queue(3)) per "context",
and throws all AIO requests of all contexts owned by a process into
the single FreeBSD per-process AIO queue.
When the process calls io_destroy(2), io_getevents(2), io_submit(2) and
io_cancel(2), my code can pick out requests owned by the specified context
from the single FreeBSD per-process AIO queue according to the per-context
request queues maintained by my code.
2. The request queue maintained by my code stores contrast information between
Linux IO control blocks (struct linux_iocb) and FreeBSD IO control blocks
(struct aiocb). FreeBSD IO control block actually exists in userland memory
space, required by FreeBSD native aio_XXXXXX(2).
3. It is quite troubling that the function io_getevents() of libaio-0.3.105
needs to use Linux-specific "struct aio_ring", which is a partial mirror
of context in user space. I would rather take the address of context in
kernel as the context ID, but the io_getevents() of libaio forces me to
take the address of the "ring" in user space as the context ID.
To my surprise, one comment line in the file "io_getevents.c" of
libaio-0.3.105 reads:
Ben will hate me for this
REFERENCE:
1. Linux kernel source code: http://www.kernel.org/pub/linux/kernel/v2.6/
(include/linux/aio_abi.h, fs/aio.c)
2. Linux manual pages: http://www.kernel.org/pub/linux/docs/manpages/
(io_setup(2), io_destroy(2), io_getevents(2), io_submit(2), io_cancel(2))
3. Linux Scalability Effort: http://lse.sourceforge.net/io/aio.html
The design notes: http://lse.sourceforge.net/io/aionotes.txt
4. The package libaio, both source and binary:
http://rpmfind.net/linux/rpm2html/search.php?query=libaio
Simple transparent interface to Linux AIO system calls.
5. Libaio-oracle: http://oss.oracle.com/projects/libaio-oracle/
POSIX AIO implementation based on Linux AIO system calls (depending on
libaio).
---snip---
Submitted by: Li, Xiao <intron@intron.ac>
- Linux returns ENOPROTOOPT in a case of not supported opt to setsockopt.
- Return EISDIR in pread() when arg is a directory.
- Return EINVAL instead of EFAULT when namelen is not correct in accept().
- Return EINVAL instead of EACCESS if invalid access mode is entered in
access().
- Return EINVAL instead of EADDRNOTAVAIL in a case of bad salen param
to bind().
Submitted by: rdivacky
Tested with: LTP (vfork01 fails now, but it seems to be a race and
not caused by those changes)
MFC after: 1 week
- add support to power off the system [2]
- check the linux magic values [3]
Submitted by: Marcin Cieslak <saper@SYSTEM.PL> [1,2]
Modelled after: linux man page of the reboot() syscall [3]
Found by: LTP testcase "reboot02" [1]
Tested with: LTP testcase "reboot02" [1,3]
MFC after: 1 week
but further on -current (still not successful, but a step into the right
direction).
Sponsored by: Google SoC 2006
Submitted by: rdivacky
Tested by: Paul Mather <paul@gromit.dlib.vt.edu>
handling for amd64 in the common code. The MD parts for amd64 are still
outstanding, but at least this fixes some panics on amd64.
Sponsored by: Google SoC 2006
Submitted by: rdivacky
Tested by: bsam
- protect td->td_proc->p_pid with the proc lock in linux_getpid
in the amd64 (= non i386) case [1]
Sponsored by: Google SoC 2006
Submitted by: rdivacky
Noticed by: netchild [1]
- TLS - complete
- pid/tid mangling - complete
- thread area - complete
- futexes - complete with issues
- clone() extension - complete with some possible minor issues
- mq*/timer*/clock* stuff - complete but untested and the mq* stuff is
disabled when not build as part of the kernel with native FreeBSD mq*
support (module support for this will come later)
Tested with:
- linux-firefox - works, tested
- linux-opera - works, tested
- linux-realplay - doesnt work, issue with futexes
- linux-skype - doesnt work, issue with futexes
- linux-rt2-demo - works, tested
- linux-acroread - doesnt work, unknown reason (coredump) and sometimes
issue with futexes
- various unix utilities in linux-base-gentoo3 and linux-base-fc4:
everything tried worked
On amd64 not everything is supported like on i386, the catchup is planned for
later when the remaining bugs in the new functions are fixed.
To test this new stuff, you have to run
sysctl compat.linux.osrelease=2.6.16
to switch back use
sysctl compat.linux.osrelease=2.4.2
Don't switch while running a linux program, strange things may or may not
happen.
Sponsored by: Google SoC 2006
Submitted by: rdivacky
Some suggestions/help by: jhb, kib, manu@NetBSD.org, netchild
Please don't style(9) the NetBSD code, we want to stay in sync. Not imported
on a vendor branch since we need local changes.
Sponsored by: Google SoC 2006
Submitted by: rdivacky
With help from: manu@NetBSD.org
Obtained from: NetBSD (linux_{futex,time}.*)
Giant VFS locking in that function.
- Remove bogus code to handle the case where namei() returns success but a
NULL vnode pointer.
- Note that this code duplicates exec_check_permissions() and annotate
where it differs.
- Hold the vnode lock longer to protect the write to set VV_TEXT in
v_vflag.
- Mark linux_uselib() MPSAFE.
Reviewed by: rwatson
ibcs2_getdents(), ibcs2_read(), ogetdirentries(), svr4_sys_getdents(),
and svr4_sys_getdents64() similar to that in getdirentries().
- Mark ibcs2_getdents(), ibcs2_read(), linux_getdents(), linux_getdents64(),
linux_readdir(), ogetdirentries(), svr4_sys_getdents(), and
svr4_sys_getdents64() MPSAFE.
mostly consists of pushing a few copyin's and copyout's up into
__semctl() as all the other callers were already doing the UIO_SYSSPACE
case. This also changes kern_semctl() to set the return value in a passed
in pointer to a register_t rather than td->td_retval[0] directly so that
callers can only set td->td_retval[0] if all the various copyout's succeed.
As a result of these changes, kern_semctl() no longer does copyin/copyout
(except for GETALL/SETALL) so simplify the locking to acquire the semakptr
mutex before the MAC check and hold it all the way until the end of the
big switch statement. The GETALL/SETALL cases have to temporarily drop it
while they do copyin/malloc and copyout. Also, simplify the SETALL case to
remove handling for a non-existent race condition.
to a copied-in copy of the 'union semun' and a uioseg to indicate which
memory space the 'buf' pointer of the union points to. This is then used
in linux_semctl() and svr4_sys_semctl() to eliminate use of the stackgap.
- Mark linux_ipc() and svr4_sys_semsys() MPSAFE.
and don't panic.
This fix is different from the patch submitted as it not only prevents
a NULL-pointer dereference, but also skips some work in this case.
Noticed by: Dmitry Ganenko <dima@apk-inform.com>
Reviewed by: rdivacky (the original version as in emulation@)
MFC after: 1 week
Security: This is a RELENG_x_y candidate (local DoS).
Go ahead by: secteam (cperciva)
Add back in a scheme to emulate old type major/minor numbers via hooks into
stat, linprocfs to return major/minors that Linux app's expect. Currently
only /dev/null is always registered. Drivers can register via the Linux
type shim similar to the ioctl shim but by using
linux_device_register_handler/linux_device_unregister_handler functions.
The structure is:
struct linux_device_handler {
char *bsd_driver_name;
char *linux_driver_name;
char *bsd_device_name;
char *linux_device_name;
int linux_major;
int linux_minor;
int linux_char_device;
};
Linprocfs uses this to display the major number of the driver. The
soon to be available linsysfs will use it to fill in the driver name.
Linux_stat uses it to translate the major/minor into Linux type values.
Note major numbers are dynamically assigned via passing in a -1 for
the major number so we don't need to keep track of them.
This is somewhat needed due to us switching to our devfs. MegaCli
will not run until I add in the linsysfs and mfi Linux compat changes.
Sponsored by: IronPort Systems
- rename some file local structure definitions, the names clash with
autogenerated names
- on !alpha add some compatibility defines for those renamed structures
- make some functions globally visible on alpha
linux_ioctl.[ch] : Implement LINUX_TIOCGPTN, which returns the pty number
linux_stats.c :
- Return the magic number for devfs.
- In various stats()-related functions, check that we're stating a
file in /dev/pts, and if so, change the st_rdev field to match what linux
expects to be there for a slave pty device. The glibc checks for this, and
their openpty() fails if it is no correct.
which existed to cleanup the linux_osname mutex. Now that MTX_SYSINIT()
has grown a SYSUNINIT to destroy mutexes on unload, the extra destroy here
was redundant and resulted in panics in debug kernels.
MFC after: 1 week
Reported by: Goran Gajic ggajic at afrodita dot rcub dot bg dot ac dot yu
they are passed by reference. Handle the difference within the
linux_ioctl_termio on the LINUX_TCFLSH path.
Submitted by: Jaroslav Drzik <jaro_AT_coop-voz_dot_sk>
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.
2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.
3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.
4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.
5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.
6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.
Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64
osf1_signal.c:1.41, amd64/amd64/trap.c:1.291, linux_socket.c:1.60,
svr4_fcntl.c:1.36, svr4_ioctl.c:1.23, svr4_ipc.c:1.18, svr4_misc.c:1.81,
svr4_signal.c:1.34, svr4_stat.c:1.21, svr4_stream.c:1.55,
svr4_termios.c:1.13, svr4_ttold.c:1.15, svr4_util.h:1.10,
ext2_alloc.c:1.43, i386/i386/trap.c:1.279, vm86.c:1.58,
unaligned.c:1.12, imgact_elf.c:1.164, ffs_alloc.c:1.133:
Now that Giant is acquired in uprintf() and tprintf(), the caller no
longer leads to acquire Giant unless it also holds another mutex that
would generate a lock order reversal when calling into these functions.
Specifically not backed out is the acquisition of Giant in nfs_socket.c
and rpcclnt.c, where local mutexes are held and would otherwise violate
the lock order with Giant.
This aligns this code more with the eventual locking of ttys.
Suggested by: bde
as they both interact with the tty code (!MPSAFE) and may sleep if the
tty buffer is full (per comment).
Modify all consumers of uprintf() and tprintf() to hold Giant around
calls into these functions. In most cases, this means adding an
acquisition of Giant immediately around the function. In some cases
(nfs_timer()), it means acquiring Giant higher up in the callout.
With these changes, UFS no longer panics on SMP when either blocks are
exhausted or inodes are exhausted under load due to races in the tty
code when running without Giant.
NB: Some reduction in calls to uprintf() in the svr4 code is probably
desirable.
NB: In the case of nfs_timer(), calling uprintf() while holding a mutex,
or even in a callout at all, is a bad idea, and will generate warnings
and potential upset. This needs to be fixed, but was a problem before
this change.
NB: uprintf()/tprintf() sleeping is generally a bad ideas, as is having
non-MPSAFE tty code.
MFC after: 1 week
so that we do not call uiomove() while IFNET_RLOCK() is held.
This eliminates the witness warning:
Calling uiomove() with the following non-sleepable locks held:
exclusive sleep mutex ifnet r = 0 (0xc096dd60) locked @
/usr/src/sys/modules/linux/../../compat/linux/linux_ioctl.c:2170
MFC after: 2 days
IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to
ifnet.if_drv_flags. Device drivers are now responsible for
synchronizing access to these flags, as they are in if_drv_flags. This
helps prevent races between the network stack and device driver in
maintaining the interface flags field.
Many __FreeBSD__ and __FreeBSD_version checks maintained and continued;
some less so.
Reviewed by: pjd, bz
MFC after: 7 days
- Conditionally grab Giant around the EISCONN hack at the end based on
debug.mpsafenet.
- Protect access to so_emuldata via SOCK_LOCK.
Reviewed by: rwatson
Approved by: re (scottl)
and extend its functionality:
value policy
0 show all mount-points without any restrictions
1 show only mount-points below jail's chroot and show only part of the
mount-point's path (if jail's chroot directory is /jails/foo and
mount-point is /jails/foo/usr/home only /usr/home will be shown)
2 show only mount-point where jail's chroot directory is placed.
Default value is 2.
Discussed with: rwatson
so do not duplicate the code in cvtstatfs().
Note, that we now need to clear fsid in freebsd4_getfsstat().
This moves all security related checks from functions like cvtstatfs()
and will allow to add more security related stuff (like statfs(2), etc.
protection for jails) a bit easier.
the type of object represented by the handle argument.
- Allow vm_mmap() to map device memory via cdev objects in addition to
vnodes and anonymous memory. Note that mmaping a cdev directly does not
currently perform any MAC checks like mapping a vnode does.
- Unbreak the DRM getbufs ioctl by having it call vm_mmap() directly on the
cdev the ioctl is acting on rather than trying to find a suitable vnode
to map from.
Reviewed by: alc, arch@
Replace a KASSERT of LINUX_IFNAMSIZ == IFNAMSIZ with a preprocessor
check and #error message. This will prevent nasty suprises if users
change IFNAMSIZ without updating the linux code appropriatly.
with the IP_HDRINCL option set. Without this change, a Linux process
with access to a raw socket could cause a kernel panic. Raw sockets
must be created by root, and are generally not consigned to untrusted
applications; hence, the security implications of this bug are
minimal. I believe this only affects 6-CURRENT on or after 2005-01-30.
Found by: Coverity Prevent analysis tool
Security: Local DOS
SIGPIPE signal for the duration of the sento-family syscalls. Use it to
replace previously added hack in Linux layer based on temporarily setting
SO_NOSIGPIPE flag.
Suggested by: alfred
for the duration of the send() call. Such approach may be less than ideal
in threading environment, when several threads share the same socket and it
might happen that several of them are calling linux_send() at the same time
with and without SO_NOSIGPIPE set.
However, such race condition is very unlikely in practice, therefore this
change provides practical improvement compared to the previous behaviour.
PR: kern/76426
Submitted by: Steven Hartland <killing@multiplay.co.uk>
MFC after: 3 days
The fundamental problem is that we get only the lower 8 bits of the
minor device number so there is no guarantee that we can actually
find the disk device in question at all.
This was probably a bigger issue pre-GEOM where the upper bits
signaled which slice were in use.
The secondary problem is how we get from (partial) dev_t to vnode.
The correct implementation will involve traversing the mount list
looking for a perfect match or a possible match (for truncated
minor).
former is callable from user space and the latter from the kernel one. Make
kernel version take additional argument which tells if the respective call
should check for additional restrictions for sending signals to suid/sugid
applications or not.
Make all emulation layers using non-checked version, since signal numbers in
emulation layers can have different meaning that in native mode and such
protection can cause misbehaviour.
As a result remove LIBTHR from the signals allowed to be delivered to a
suid/sugid application.
Requested (sorta) by: rwatson
MFC after: 2 weeks
duplicating the contents of the same functions inline.
- Consolidate common code to convert a BSD statfs struct to a Linux struct
into a static worker function.
structure in the struct pointed to by the 3rd argument for IPC_STAT and
get rid of the 4th argument. The old way returned a pointer into the
kernel array that the calling function would then access afterwards
without holding the appropriate locks and doing non-lock-safe things like
copyout() with the data anyways. This change removes that unsafeness and
resulting race conditions as well as simplifying the interface.
- Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(),
fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of
code duplication for freebsd4 and netbsd compatability system calls.
- Add a new lookup function kern_alternate_path() that looks up a filename
under an alternate prefix and determines which filename should be used.
This is basically a more general version of linux_emul_convpath() that
can be shared by all the ABIs thus allowing for further reduction of
code duplication.
providing special version of CDIOCREADSUBCHANNEL ioctl(), which assumes that
result has to be placed into kernel space not user space. In the long run
more generic solution has to be designed WRT emulating various ioctl()s
that operate on userspace buffers, but right now there is only one such
ioctl() is emulated, so that it makes little sense.
MFC after: 2 weeks
